Milk is considered acidic, by itself and in its varying forms including sour cream, yogurt, ice cream and various cheeses (including cottage cheese and Parmesan). Along with milk, eggs are also considered acidic.
There are a number of fish that fit into the acid producing category. These include trout, haddock, cod and herring.
Meats are made up of amino acids. When processed in the body they are considered acidic. The meats range from beef, poultry to pork, and also include such items as processed meat. Examples of these are beef in its various unprocessed forms, chicken, turkey, and pork in its various unprocessed forms. Processed meats include salami and lunch meat.
Peas, lentils and peanuts are all legumes that cause acidity, and walnuts are a nut that causes acidity. Grains that cause acidity include wheat, rye, rice and processed corn.
Processed sugar (including brown sugar) and molasses are sweeteners that make the body acidic. Sweets that make the body acidic include such things as jam, cake and milk chocolate. Artificial sweeteners also make the body acidic.